breastfeeding worries

hello po. it's been 4days today since i delivered my baby via C section at nagstart kaagad ako sa pag breastfeed. ask ko lang, bakit kaya mahapdi nipples ko kapag pinapadede si baby? namula sya ngayon eh at nung isang araw ay left breast ko lng ang masakit, pero ngayon both breasts na. what should i do? does that indicate na talagang walang nakukuha sakin na breast milk si baby? help or any advice please. thanks.